The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test track. A tire graded 200 would wear twice as long on the government test course under specified test conditions as a tire graded 100. It's wrong to link treadwear grades with your projected tire mileage. The relative performance of tires depends upon the actual conditions of their use, and may vary due to how often they're rotated and your other service practices, your driving habits, differences in road characteristics, and even climate.

Traction grades, from highest to lowest, are AA, A, B and C. They represent the tire's ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete.

The temperature grades, from highest to lowest, are A, B and C. These represent the tire's resistance to the generation of heat when tested under controlled conditions on a specified indoor laboratory test wheel.

The valve, fitted in the wheel, ensures that the tire can be filled with air. The correct valve is required for the correct wheel / tire assembly. A slow loss of air pressure can result from a defective valve. The valve cap should always be fitted to the valve in order to protect the valve core from dirt and moisture.